THE BOOK OF NATURE STUDY 



vestige or is wanting altogether. In pigeons and owls it is also 

 wanting. In some of the ostrich tribe, such as the emu and 



cassowary, it is as long as the main 

 feather (Fig. 22) . Finally, the great 

 flight-feathers of the wing and the 

 large tail-feathers never develop an 

 after-shaft. 



The downy covering of nestling 

 birds should be briefly referred to. 

 This covering, in birds which are 

 active at birth, is more feather-like 

 than that which clothes nestlings 

 which remain long in the nest, such 

 as owls and petrels, for example. 



Since the nestling periods present 

 one of the most interesting and most 

 instructive phases of bird-life, some 

 effort should be made, even in town 

 schools, to secure one or two of the 

 more striking types of nestlings. 



Young pigeons are not difficult 

 to procure, and these are interesting 

 as showing a degenerate down 



emu, showing the after-shaft as lu the down tufts bd re _ 



large as the mam-shaft. & ' . 



duced to hair-like threads ; while in 



young sparrows and young crows no down is ever developed 

 (see p. 102). 



But besides these which should be kept for permanent 

 reference, preferably in a bottle of spirits, or failing that should 

 be stuffed examples should be obtained of, say, a nestling of the 

 common pheasant, or of the common fowl, and of a duckling, 

 these showing, in addition to the peculiarities of plumage, interest- 

 ing differences in the development of the wings (p. 102). 



In most of these young birds, in the young pigeon, for example, 

 it will be noticed that the nestling down feathers are shed in a 

 very peculiar way, inasmuch as they do not drop out, but are 

 thrust out upon the tips of the succeeding permanent feathers, 

 whereupon they may remain for some time. 



FlG. 22. A contour-feather of an 



